Socks are commercially available which employ materials with a high degree of water absorbability and rapid drying properties, as well as materials with a mesh structure, aiming to produce a sock with an internal environment as comfortable to the wearer as possible.
Heretofore, there has also been disclosed a sock with a plain knitted portion and a pile knitted portion disposed in a lattice configuration in the arch portion of the sock, with increased air permeability at specified areas of the sole portion.
However, due to the fact that the temperature of the entire sole rises during walking, there is the problem that the sock of Japanese Laid-Open Patent Application No. 2001-295104, which increases air permeability only in the arch portion, an area of the sole which does not touch the ground, cannot increase air permeability as fully as expected, simply because humid air is trapped inside the shoe.
A sock is disclosed in Japanese Utility Model Registration No. 3113253 in which a sock has a knitted structure with mesh knitting at the base portions of toes on the instep side and the sole side, and in the arch portion, and with pile knitting in the sole portion and the toe portion. However, the sock of Japanese Utility Model Registration No. 3113253 had improved air permeability primarily only at the base portions of toes and in the arch portion, which are areas of the sole which do not touch the ground. Therefore, there is the problem that sufficient ventilation cannot be achieved, even with the alternating mesh knitting and pile knitting being additionally disposed on the front of the ankle and on the instep portion, due to the fact that no provision was made for air to escape from the sock or from the shoe.
In Japanese Utility Model Registration No. 3121397 given below, there is disclosed a sock with a band with uneven configuration formed by varying the pile lengths provided at a uniform width on the outer surface of the sole portion, and with a plurality of uneven bands formed on the front side of the arch portion across the entire circumference of the foot from the sole to the instep.
However, in the case of the above-described sock of Japanese Utility Model Registration No. 3121397, there is also the problem that sufficient ventilation cannot be achieved, since no provision was made for humid air to escape from the sock or from the shoe. The steamy feeling is not eliminated, even if an uneven band is formed along the entire circumference of the foot from the sole to the instep, since the humid air circulates along this uneven band.